#include<stdio.h>
void reverse_string(char s[])
{
	size_t len = strlen(s);
	char tmp = s[0];
	s[0] = s[len - 1];
	s[len - 1] = '\0';
	if (strlen(s + 1) >= 2)
		reverse_string(s + 1);
	s[len - 1] = tmp;
}
int main()
{
	char arr[] = "zsfdgfdhftyhfg";
	reverse_string(arr);
	printf("%s\n", arr);//fedcba

	return 0;
}